American here. Here's the three common contexts for tipping. Everything else is something someone's trying to make a thing rather than actually a thing:
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Restaurants: If someone is bringing food from the Kitchen to your table
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Delivery: If someone's delivering food. Or they're personally delivering groceries.
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Transportation: If someone's driving you personally. Like a Taxi.
Some say you should tip bathroom attendants. I've never even seen a bathroom attendant, but that seems like such a bizarre job to tip for, even by American standards.